Source for Paper A: Rat helps hook school to Internet

1- Argument: Rats can have a positive effect on society, because rats can be trained to do useful things.

2- Audience: Elementary or middle school children who read Current Science.

3- Goal: To cause people to change their ideas that rats are just filthy vermin by introducing people to the idea that rats can be trained to do useful things.

4- How the argument was made:
Ethos: Because the article is directed toward schoolchildren, the very first sentence establishes a connection by referring to students using computers at school.
Typical: The example used in this argument is not entirely typical. Not all rats can be trained to perform this kind of work. However, it would be more typical had it been mentioned that the rat involved is a fancy rat, not a wild rat.
Pathos: The word choice used in this article encourages the reader to think of a rat in a positive way. "Tiny" emphasizes the small, cute nature of the rat. Referring to the rat as "she" and "her" instead of "it" personifies the rat, as does referring to favorite foods and retirement time.

5- Effectiveness: This article probably convinces much of its audience that rats can be useful instead of gross.